Deteriorating ecology of lakes, the presence of untreated sewage, and concrete embankments that declare to assist waterbody rejuvenation have led to a gentle decline within the variety of water birds present in Bengaluru, in line with specialists and environmentalists.
Chicken watchers and ornithologists say the decline might be wherever between 80% to 90% over the past two to 3 a long time. In response to ornithologist and scientist S Subramanya, using civil engineering methods for lake improvement has a profound impression on the water birds.
“The lakes was shallow water basins with various water depths and completely different birds would occupy completely different depths of water. Now, the lakes are often desilted uniformly and solely a small part of birds profit from that,” he defined. As an example, deep water of uniform depth discourages waders, various populations of which migrate to India, together with the southern peninsula in winter.
Subramanya added that the lakes, which was seasonal have turned perennial because of the influx of sewage water. “The construction and ecology of those lakes have modified and as a consequence, the water hen inhabitants has nosedived,” he added.
Chicken watchers who replace lists of varied species on on-line platforms additionally seen increased presence of birds of a single species fairly than various ones.
In response to a joint report by Council of Scientific and Industrial Analysis (CSIR) and Nationwide Environmental Analysis Institute (NEERI), 19 of the 205 extant lakes (out of an earlier estimate of 250) in and across the metropolis are utterly encroached. And solely 21 have water that’s match to drink. A report by the Karnataka State Air pollution Management Board (KSPCB) in 2020 urged that not even one lake had water match for ingesting.
Between 2008 and 2020, the BBMP claimed to have developed round 80 out of 205 lakes with one other 20 beneath numerous phases of completion, however this improvement usually refers back to the constructing of concrete buildings across the lake fairly than any deal with the ecology itself.
In response to State of India’s Birds 2020 , a report on the distribution and conservation of birds, there was a “gradual decline” within the inhabitants of birds within the metro cities of Bengaluru, Chennai, Delhi, Hyderabad, Kolkata and Mumbai.
Birders and environmentalists additionally referred to “man-made issues” resembling speedy and unplanned urbanisation that’s changing the habitats of those winged creatures. Furthermore, conservation efforts by the federal government usually refers back to the authorized safety of animals, they added.
Essentially the most noticeable change in Bengaluru is the disappearance and an explosion within the variety of pigeons and barn owls, specialists mentioned.
“Pigeons are historically recognized to put eggs primarily based on the supply of meals. However they breed all 12 months now since there may be feeding by people that has altered the very nature of their reproductive buildings and brought on an explosion of their numbers,” Chandrakanth, previously with the College of Agricultural Sciences (UAS) in Bengaluru, mentioned.
Pigeons now are likely to nest in each attainable concrete construction, together with residences and different buildings to keep away from threats from different predators as nicely, specialists mentioned.
Research confirmed that their excreta is able to inflicting a number of illnesses and is extraordinarily acidic that may trigger long-term injury to buildings and people and unfold salmonella germs . Equally, Barn Owls which have been a uncommon species of hen within the metropolis, additionally nest in house complexes as open rubbish attracts rats that are simple prey for these nocturnal birds, specialists added.
The sight of walkers and joggers feeding birds with every kind of meals resembling biscuits, grains, puffed rice and even bread is a typical sight in areas resembling Cubbon Park and Lal Bagh .
The usage of chemical substances and pesticides has additionally impacted the well being of those birds who feed on seeds and bugs in these areas.
The difficulty in assessing the precise impression is the dearth of correct research to find out the rise in inhabitants of some birds and disappearance of others, birders and ornithologists mentioned.
“Of the 261 species for which long-term developments might be decided (i.e. not unsure or information poor), 52% have declined since 2000. In all, 43% of species confirmed a long-term development that was steady and 5% confirmed an growing development,” in line with the report by CSIR and NEERI.